Ukraine Protests In London, Moscow And Washington, As Tensions With Russia Escalate (PICTURES)

Hundreds of British-based Ukrainians gathered outside the Russian Embassy in London to protest against the build-up of troops in the Crimea region. The demonstrators chanted and held banners demanding "Hands off Ukraine".

Many of them waved placards accusing president Vladimir Putin of being the "Russian aggressor" and they sang: "Putin is a murderer" and "stop the occupation".

Activists calling for Putin to pull troops out of the country also gathered in Kiev, New York, Washington DC, Moscow and the Lithuanian capital of Vilnius.

Members of the punk protest band Pussy Riot were seen in Manej square in the Russian capital.

Britain will now not take part in preparatory talks due to be held in the coming days for the summit in Sochi, over Russia's decision to take military action in Ukraine, Foreign Office officials have confirmed.